[Box Backup] Moving a server to RAID

Jamie Neil boxbackup@fluffy.co.uk
Tue, 15 Mar 2005 10:38:49 +0000


dave bamford wrote:
> 2. Would you recommend the mobo RAID or the FC3 sw RAID?

Unless you are using a _true_ hardware RAID controller (like the 3ware 
ones) then you are better off using software RAID on Linux for a number 
of reasons:

1) Cheap hardware RAID controllers are essentially software RAID in 
disguise - no cache and most of the processing is done by the CPU.

2) Linux drivers for most RAID controllers are not very good, and some 
are binary only and so only work on specific kernel versions.

3) If the controller fails, you'll need to get another one exactly the 
same to boot your array (with embedded controllers this is even more of 
a problem). With software RAID you can move the array to another system 
and it will work fine.

4) Performance is roughly the same.

The two main benefits of hardware RAID over software is caching and hot 
plug facilities, however these are only available on the higher end 
controllers.

-- 
Jamie Neil | <jamie@versado.net> | 0870 7777 454
Versado I.T. Services Ltd. | http://versado.net/ | 0845 450 1254